Hi Hopeful!
My husband and I are caught up in exactly this dilemma and I am afraid I don't have an answer.
My neuropathy is hereditary, CMT, and progressive, much worse in the last six months, and my muscle loss is visible. I have never been able to do anything athletic, but I did hike extensively as long as there was limited elevation gain. We have been trying to get back to walking, just a couple miles around a lake nearby. On Monday we tried and I had to be partially carried to bed! I was unable to walk unassisted by the evening. Tuesday was rough but I was better by today and we tried again. Like you I take a Percocet before exercising because I know it will hurt.
The muscle loss is inexorable but can I slow it down, or strengthen the unaffected muscles by walking or am I just injuring myself more? I love being outside and my husband feels the psychological benefit is real even if I am not gaining anything physically. But am I hurting myself? I have not been able to figure that one out.
Do you find that there are other benefits to walking? Does it help your mood as it does mine? I don't see how I will be able to stand up and cook dinner the way my legs feel now, but I still think it was worth it. If I knew it was accelerating my disability long term I wouldn't want to risk it.